Counter-Strike: Source

Multi player only game with two teams, the terrorists and the counter-terrorists. At the start of each round all members of a team spawn in their buy zone were they can use the money they have to buy weapons. You gain money by killing the enemy and completing the goals of your team.

Counter-Strike: Global offensive

Once more the counter-terrorists and terrorists try to kill each other. The levels you can play are Dust 2 and some other levels that are not Dust 2. If you vote for anything else then Dust 2 you are a Noob. I was a noob for two hours until i got my first kill then i started to vote on Dust 2 like everyone else. In total of four hours playing i manage to get 12 kills total. It's less then the average time a counter-strike player spend on Dust 2 each day :). Grinding that much is not for me so i think i skip this game.